Crystallise the sulfate from 0.4M H2SO4, or precipitate it from an aqueous solution with EtOH. It is efflorescent in dry air, and is converted to the tetrahydrate at 57o, then to the monohydrate at 65o (or by heating the heptahydrate in a vacuum at 140o). It forms a brown-black complex, FeSO4.NO, with nitric oxide and is used in a qualitative test for nitrates (“brown ring” test).
Used in quantitative analysis of nitrates .
In manufacture of Fe, Fe Compounds, other sulfates; in Fe electroplating baths; in fertilizer; as food and feed supplement; in radiation dosimeters; as reducing agent in chemical processes; as wood preservative; as weed-killer; in prevention of chlorosis in plants; in other pesticides; in writing ink; in process engraving and lithography; as dye for leather; in etching aluminum; in water treatment; in qualitative analysis ("brown ring" test for nitrates); as polymerization catalyst.
As analytical reagent; as raw material for ferrite; raw material to produce magnetic iron oxide, iron(III) oxide and iron blue inorganic pigment, iron catalyst and poly iron sulfate; as chromatographic reagent. In agriculture, it is used as pesticide in agriculture to control wheat smut, scab of apple and bear, fruit tree decay; as fertilizer to remove moss and lichen of food trunk. Medically it is used as local astringent, blood tonic and anti-anemia. Ferrous sulfate heptahydrate (feed grade) can be used as the iron fortifier for feed additive. Ferrous sulfate heptahydrate (food grade) is used as nutrition supplements, such as iron fortifier, coloring agent for fruit and vegetable. According to Chinese regulation, it can be used in following foods and with allowed amounts:
Sweets with filling and salt: 3000~6000 mg/kg;
Cereals with high iron content and corresponding products (maximum daily consumption 50g): 860~960 mg/kg;
Dairy and infant foods: 300-500 mg/kg;
Cereals and corresponding products: 120~140 mg/kg;
Beverages: 50~100 mg/kg. It is used to produce iron salt, iron oxide pigment, mordant, water purifier, preservatives, disinfectant, etc.
INGESTION: abdominal pain, retching, diarrhea, dehydration, shock, pallor, cyanosis, rapid or weak pulse, shallow respiration, low blood pressure.
light blue or light blue-green solid
Storage and Transport
Stored in well-ventilated area, low temperature and dry.
Blue-green crystals (monoclinic system) or granules, odorless. Soluble in water, slightly soluble in alcohol, soluble in anhydrous methanol.
Water, carbon dioxide, dry powder, sand.
Flammability Hazardous Characteristics
Not flammable, change into ferric oxide smoke at high temperature.
A greenish or yellow-brown crystalline solid. Density 15.0 lb /gal. Melts at 64°C and loses the seven waters of hydration at 90°C. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. Used for water or sewage treatment, as a fertilizer ingredient.
Solubility in water (g/100mL)
Dissolved grams in 100 mL water at different temperatures (°C):
Oral-rat LD50: 1389 mg/kg; oral-mouse LD50: 1520 mg/kg.
- By-product Method: byproduct of titanium dioxide production:
Titanite is decomposed with sulfuric acid to obtain titanium dioxide, ferrous sulfate(II) and ferric sulfate (III). Iron (III) compounds are reduced to obtain iron (II) compounds. The mixture is then cooled and crystallized to form ferrous sulfate.
Scrap iron is dissolved with a mixture of diluted sulfuric acid solution and mother solution. The reaction temperature should be below 80°C, otherwise, it results in the sedimentation of ferrous sulfate monohydrate. Clarification is applied to remove impurities from the slightly acidic ferrous sulfate solution. Cooling and centrifugation are carried out obtain light-green ferrous sulfate.
Ferrous sulfate heptahydrate is a weak reducing agent.
ChEBI: A hydrate that is the heptahydrate form of iron(2+) sulfate. It is used as a source of iron in the treatment of iron-deficiency anaemia (generally in liquid-dosage treatments; for solid-dosage treatments, the monohydrate is normally used).
Air & Water Reactions